1. Field of the Invention
The present invention relates to a rolling mill stand with arrangements for the spaced-apart support of an upper work roll of the stand. Specifically, the invention relates to a rolling mill stand with work rolls which are supported in chocks, wherein the upper work roll can be raised from the lower work roll by means of balancing cylinders and wherein the upper work roll can be supported for a roll change on the balancing cylinders above the lower work roll in order to avoid contact of the bodies of the rolls, wherein the support is effected by mechanical means of the chocks.
2. Description of the Related Art
In sets of work rolls, it is known in the art to equip the chocks of the upper work rolls and the lower work rolls with projections and recesses, for example, pins and holes, so that during normal operation the projections engage more or less in the recesses; in order to carry out the disassembly, the upper work rolls are raised together with their chocks and are then axially displaced, so that the projections are moved out of the regions of the recesses and can be placed on portions of the chocks which are located at a higher lever, so that the bodies of the two work rolls of a set no longer contact each other and, thus, the surface properties of the roll bodies are not impaired by the contact.
However, it has been found that the time required by a roll change, which results in an undesirable idle period of the stand, is increased in a disadvantageous manner by the necessity of the axial displacement of the upper work rolls after the work roll has been raised. Another disadvantage is the fact that the structural length of the roll set to be exchanged is increased by the required additional axial displacements, so that the manipulation of the roll set is more difficult.
Rolling mill stands which are in use today often have additional possibilities of adjustment, in which the work rolls can be additionally displaced axially, relative to each other during the rolling operation, for example, in order to be able to place the ends of the bodies of work rolls above edges of the rolled material to change the effective crown or camber by means of a special shape or surface contour (CVC). In rolls of this type, the recesses must be extremely long, so that the relative axial displacement is not impaired during the operation; in addition, for the roll change, the rolls must be displaced even at a greater distance relative to each other.